Which built-in Django signals besides post_save should you know?
PICTURE THIS: DJANGO MVT
Simple meaning
pre_save and pre_delete/post_delete wrap persistence.
WHY — Signals instead of guessing?
Why interviewers care about Signals:
who only read docs from people who shipped.
and tied to Python work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Define it
pre_save and pre_delete/post_delete wrap persistence.
- 2m2m_changed fires when a
many-to-many relation is updated.
- 3request_started/request_finished and connection-level signals
exist, plus django.contrib.auth's user_logged_in.
- 4Pick the signal that
matches the actual event rather than overloading post_save.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
pre_save and pre_delete/post_delete wrap persistence. m2m_changed fires when a many-to-many relation is updated.